Balanced Laminating Over Melamine

Here's a detailed discussion about whether it's okay to apply laminate over just one face of a melamine door, and about various other ways to achieve the same product. October 12, 2012

QuestionEvery time I talk to my plastic lamination outsource vendor, he gives me shit about how I make Formica laminated commercial cabinet doors. Instead of going through all the trouble of having him laminate plastic to one face of particleboard and white cabinet liner plastic to the other, I simply contact cement the plastic to one face of two-face melamine particleboard, trim, and edgeband. The result looks exactly the same as what the laminator gives me, and is considerably cheaper given that the white liner is omitted and the whole operation involves no press time.

He claims that this is not a balanced panel and will surely warp, but I have done this hundreds of times and never had a warp any worse that you can get with his "proper" method. Does anyone else do this?

Forum Responses(Cabinetmaking Forum)
From contributor P:My very first Formica kitchen was built the way you do your doors. The material back then was called Kortron. It had a shiny white baked-on finish on one side and plastic laminate applied with contact cement on the other. It warped, so I started balancing the panels. If your mileage varies it is only because you are lucky.

From contributor D:Like you, we have been laminating over white melamine for years without a failure. However, for larger projects we will often purchase MDF door board that has a white liner on one side. It gives a little more peace of mind. We often use PVC edges so we lay up in sheets, cut and then band. If we are doing HPL edges, we band and then face.
From contributor C:I'll admit we have done the same in tight deadlines, but now I actually have 11/16 particleboard with a liner on one side and no laminate on the other. This allows us to lay up fast and in a balanced panel fashion. We have not had failures in the past, but it is not balanced.

I studied the time to pull a sheet on melamine with paint grade on one side and melamine on the other, opening the box of p-lam and laying it up, trimming and then walking it to the saw, versus buying pre-laid up with a liner, set at the saw, and the conclusion is absolutely obscene. We expend waste of 30.00 in labor doing it ourselves rather having it done for us. On 40 sheets, that's 1200! And on a job that size we cannot afford delamination, warped panels or the loss of time on the labor, when it can go to many other areas.

From contributor T:I think that the bigger factor is that it is a lot cheaper to just buy the panels laminated. I can usually get them within a few days. And yes, balance the panels, or you will regret it.
From contributor L:You are lucky! I've seen this fail several times and won't do it in our shop. We buy pre-laminated panels as much as possible, almost always with laminate both sides. Cabinet liner is better than nothing, but still not truly balanced.

Fact is, pre-lam is cheaper than doing it in house, and you get a better product because they use hard glue, not contact.

From contributor K:I'm surprised nobody has mentioned that using contact cement does not cause unbalancing because it's not a rigid glue. The questioner's technique works fine and is not unbalanced. But contributor L's point is correct. Post laminating melamine is still not cheaper than buying a pre-laminated panel with a cabinet liner back. What you save in material you more than lose in labor.
From the original questioner:I have to say that it is just as cheap for me to cut up melamine into door sizes, cut up the Formica slightly oversized, contact cement the Formica on and trim, as it is for me to order laid up panels pre-cut to door sizes. (I have to order pre-cut since I cannot cut the laminated panels myself without a chippy saw kerf on one side or the other.) At this point, either way, the panels have to be edgebanded and there is no labor difference there.

Maybe my laminator is ripping me off. But I am prone to think that there is just as much labor for him to spread glue on two sides of PB, stack the panels in his press, take them off his press and onto his beam saw to cut to size, and then strap all the pieces and send them out to me. And maybe I have always gotten away with this because I always use two face melamine (not paint grade back or one sided) and solvent based contact cement. I was always told that Formica laminate was developed to have the exact same coefficient of expansion-contraction as wood itself.

One final point: I have actually on occasion used my laminator for big door jobs, and I have experienced some warping even then.

From contributor C:Yikes - so sanding the melamine does not take time? Apparently we are paying a different rate than you are. We use the paint grade or good one side so we don't have to sand.
From contributor T:The main reason that is cheaper is because they buy laminate at the wholesale price. Give West Coast Laminates a call.

You have to balance the panel with the same thickness material on both sides. Instead of cabinet liner you have to use 949 of the same thickness as the face.

I doubt the comment about contact cement, as that has not been my experience. I mean if you just put a sheet of particleboard in the sun, it will warp because of the difference it causes in moisture content.

From contributor S:I can't even buy the sheet laminate as cheap as I can buy it already laid up. My price for a 4x8 sheet of Formica from my supplier is about $50-55. Two of those with a sheet of MDF will run me about $130 or so. Plus the cost of the contact cement and a roller. And the labor to lay it up. I can order a 2-sided 4x8 laid up Formica panel with 3/4 MDF core for $100. All I have to do is cut and edgeband. No contact cement.
From contributor L:"Formica laminate was developed to have the exact same coefficient of expansion-contraction as wood itself." Not true! For a start, laminate is directional. It moves more in one direction than the other. That's why you always lay the laminate the same way front and back.

We just ordered 20 .75 x 4x8 sheets to finish out a job. Lam one face, liner back (not ideal, but the customer specified). Price was $68. 3/4" particleboard core, Wilson VG lam, white cab liner. I don't see any way we could beat that price in our shop using contact cement. You guys must be a lot faster at laminating than our guys.

From contributor R:We laminated to melamine for many years and rarely had a problem. However, melamine backed doors are not allowed under AWI Custom Grade, and almost all of our work is AWI specified. I know of a couple cabinetmakers who ended up replacing every door and drawer front in a large job because the architect insisted that they meet the spec. Silly or not, it happened, and I didn't want to get caught that way, so I started making balanced panels. I also used the fact that our panels were balanced to distinguish us in yet another way from our competition.

I made a relatively small investment in used panel layup technology, and found that we could make balanced panels less expensively than melamine backed panels. We went from 12-15 minutes per side spraying and laying contact to about 4 minutes for 2 sides. We buy white V Grade in bulk and core in bulk so we get good materials prices. The PVA glue we use is about a third the cost of contact. It's also non-toxic, non-flammable and has no VOCs. The glue line is hard, not flexible like contact, so there is no shrinkage from side to side. We can do 150 panels in a shift and we often laminate for others. Among the other benefits of this system is that we moved to miter-folding most of our straight laminate countertops, so we lay up countertop blanks and have cut our counter assembly times in half. All in all, a very positive evolution.

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